Be careful when messing with partitioning tools. From the way you asked your question I tend to assume you do not really know what you are doing. If you are seeing a drive called sdd1 you probably have more than one hard disk in that machine.
If you make a mistake you might erase data you don't want to erase.
For that reason I could not agree more with what linux_walt said. Tell us everything you did to get to that error... What tool are you using, what commands did you issue, etc...
Also provide some information about the machine you are installing to. How many hard drives, what size do the have each. Does any one of them contain data you want to keep etc.
You may also want to post the output of the following commands, all run from a root terminal in the live system:
(lists all available drives)
mount | grep dev/sd
(shows where drives are mounted)
(shows free space on drives)